/*
 *  OGF/Graphite: Geometry and Graphics Programming Library + Utilities
 *  Copyright (C) 2000 Bruno Levy
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  If you modify this software, you should include a notice giving the
 *  name of the person performing the modification, the date of modification,
 *  and the reason for such modification.
 *
 *  Contact: Bruno Levy
 *
 *     levy@loria.fr
 *
 *     ISA Project
 *     LORIA, INRIA Lorraine, 
 *     Campus Scientifique, BP 239
 *     54506 VANDOEUVRE LES NANCY CEDEX 
 *     FRANCE
 *
 *  Note that the GNU General Public License does not permit incorporating
 *  the Software into proprietary programs. 
 */
 
 
 

#ifndef __OGF_BASIC_TYPES_COUNTED__
#define __OGF_BASIC_TYPES_COUNTED__

#include <OGF/basic/common/common.h>
#include <OGF/basic/types/types.h>
#include <OGF/basic/types/smart_pointer.h>
#include <OGF/basic/debug/assert.h>

namespace OGF {

//____________________________________________________________________________

/**
 * This is the base class to be used for objects having
 * "reference count" memory management. They can be 
 * referred to by using SmartPointer<T>, calling ref()
 * and unref() when necessary.
 * @see SmartPointer
 */

    class BASIC_API Counted {

    public:
        Counted() ;
        virtual ~Counted() ;

        void ref() const ;
        void unref() const ;
        bool is_shared() const ;

        static void ref(const Counted* counted) ;
        static void unref(const Counted* counted) ;

    protected:
    private:
        int nb_refs_ ;
    } ;

//____________________________________________________________________________

    inline Counted::Counted() : nb_refs_(0) {
    }

    inline void Counted::ref() const {
        Counted* non_const_this = (Counted *)this ;
        non_const_this-> nb_refs_++ ;
    }

    inline void Counted::unref() const {
        Counted* non_const_this = (Counted *)this ;    
        non_const_this-> nb_refs_-- ;

        ogf_assert(nb_refs_ >= 0) ;
        
        if(nb_refs_ == 0) {
            delete this ;
        }
    }

    inline bool Counted::is_shared() const {
        return (nb_refs_ > 1) ;
    }

}

#endif
